Hmm. It looks like the government asserts that they can seize a device if the owner does not provide a password. This is a good point and answers my search v. seizure objection above.

You say CBP is "empowered" to seize a device if the owner refuses to provide a password but I can't find a statute that authorizes it or precedent squarely saying the 4th Amendment allows this. The scope of the border search exception isn't settled. So the next argument available is that the executive is wrong and CBP does not have the constitutional authority to seize a device merely because the owner refuses to provide a password. That's obviously a much bigger argument and who knows if it would work, though this case sorta feels like it could become a marquee 4A case.

"The ACLU argues that the Fourth Amendment does apply in these situations, at least to electronic devices, because they contain so much private information. But the law is very unsettled, and the Supreme Court has not addressed the issue."

https://www.aclumaine.org/know-your-rights/electronic-device...